Geographic origin and the cardiovascular risk profile – The Cardiovascular Risk in Young Finns Study

Background: Since the 1940’s, coronary heart disease (CHD) has been recognized as a major cause of death in the developed countries. Men born in eastern Finland were found to have internationally high CHD mortality in the late 1960’s. As a result, the “North Karelia Project” was launched, aiming to decrease CHD risk factors especially in the high risk areas. Since then, CHD mortality rates have decreased significantly in Finland with over two thirds of the decline explained by favourable changes in modifiable risk factors. Despite the overall reduction, regional differences in the rates are still seen. Although regularly studied, the current regional differences in Finland in CHD risk factors and surrogate markers subclinical atherosclerosis are thoroughly investigated. Aims: This thesis aimed to investigate current and 31-year longitudinal CHD risk factors between eastern and western Finns, to examine east-west differences in subclinical atherosclerosis measured by carotid intima-media thickness (IMT) and in cardiac left ventricular (LV) structure and function, to explore CHD risk factors, carotid IMT and left ventricular structure and function between urban and rural Finns, and to study the association of migration with CHD risk factors and carotid IMT. Participants and methods: This thesis uses data from the Cardiovascular Risk in Young Finns Study which is a prospective multicentre cohort launched in 1980. CHD risk factors have been measured from the participants repeatedly since the baseline study. Carotid IMT was first measured in 2001 from the participants and echocardiography was included in 2011, when over 57% of the original study population participated in the latest follow-up study at the age of 34–49. Results: In 2011 CHD risk factor profile between participants with eastern or western baseline origin was essentially similar. However, eastern participants have excessive risk in longitudinal risk factor analyses and they have higher carotid IMT, LV mass and worse LV diastolic function than western participants. Participants with urban baseline origin have lower CHD risk factor levels and LVM compared to rural participants. Participants who migrated from east-to-west or rural-to-urban have currently lower CHD risk factor levels and carotid IMT compared to participants who stayed in east/rural areas, respectively. Conclusions: Differences between eastern and western Finns in CHD risk factor levels are levelling off but can still be found in carotid IMT, LV mass and diastolic function, and in longitudinal CHD risk factor analyses. Urban Finns have lower CHD risk factor levels compared to rural Finns. Migration from areas characterised by higher CHD risk factor levels is associated with improvements in cardiovascular health

Coronary heart disease risk factor levels in eastern and western Finland from 1980 to 2011 in the cardiovascular risk in Young Finns study

Background and aims: In the 1960s and 1970s, Finland, mortality due to coronary heart disease (CHD) was over 30% higher among Finns residing in the east of the country compared with those residing in the west. Today, CHD mortality remains 20% higher among eastern Finns. The higher incidence of CHD mortality among eastern Finns has largely been explained by higher risk factor levels. Using a unique longitudinal cohort, we aimed to determine if participants who resided in eastern Finland during childhood had higher CHD risk factors in adulthood and from childhood to adulthood. Methods: The study population included 2063 participants of the Cardiovascular Risk in Young Finns Study, born during the period 1962-1977, with risk factor data available from baseline (1980) when participants were aged 3-18 years, and had risk factor data collected again in adulthood (2011) when aged 34-49 years. Results: Adult CHD risk factor profile was similar for those who resided in eastern or western Finland in childhood. Over life-course from 1980 to 2011, those subjects with childhood residency in eastern Finland had, on average, higher systolic (p = 0.006) and diastolic (p = 0.0009) blood pressures, total (p = 0.01) and LDLcholesterol (p = 0.01), triglycerides (p = 0.04), apoB (p = 0.02), and serum glucose (p Conclusions: Our sample of adult Finns aged 34-49 years had a similar CHD risk factor profile irrespective of whether they resided in eastern or western Finland during their childhood. However, when considering participants risk factor profiles over a 31-year period, those who resided in eastern Finland in childhood were associated with a less favorable CHD risk factor profile than those who resided in western Finland in childhood. The observed differences suggest that future CHD mortality might remain higher in eastern Finland compared with western Finland.Peer reviewe

CVD risk factors and surrogate markers - Urban-rural differences

Aims: Disparity in cardiovascular disease (CVD) mortality and risk factor levels between urban and rural regions has been confirmed worldwide. The aim of this study was to examine how living in different community types (urban-rural) in childhood and adulthood are related to cardiovascular risk factors and surrogate markers of CVD such as carotid intima-media thickness (IMT) and left ventricular mass (LVM). Methods: The study population comprised 2903 participants (54.1% female, mean age 10.5 years in 1980) of the Cardiovascular Risk in Young Finns Study who had been clinically examined in 1980 (age 3-18 years) and had participated in at least one adult follow-up (2001-2011). Results: In adulthood, urban residents had lower systolic blood pressure (-1 mmHg), LDL-cholesterol (-0.05 mmol/l), lower body mass index (-1.0 kg/m(2)) and glycosylated haemoglobin levels (-0.05 mmol/mol), and lower prevalence of metabolic syndrome (19.9 v. 23.7%) than their rural counterparts. In addition, participants continuously living in urban areas had significantly lower IMT (-0.01 mm), LVM (1.59 g/m(2.7)) and pulse wave velocity (-0.22 m/s) and higher carotid artery compliance (0.07%/10 mmHg) compared to persistently rural residents. The differences in surrogate markers of CVD were only partially attenuated when adjusted for cardiovascular risk factors. Conclusions: Participants living in urban communities had a more favourable cardiovascular risk factor profile than rural residents. Furthermore, participants continuously living in urban areas had less subclinical markers related to CVD compared with participants living in rural areas. Urban-rural differences in cardiovascular health might provide important opportunities for optimizing prevention by targeting areas of highest need.</p